托福阅读:The Parts of Metabolism

新陈代谢与我们的身体健康息息相关，而新城代谢究竟是什么呢?下面的新托福考试阅读练习资料会为你解答。

What is metabolism really? Statements like “he can eat a lot because he has a fast metabolism” are somewhat misleading.

Metabolism isn’t about the digestion of food in your stomach; it’s the name given to all of the chemical changes that occur in an organism’s tissue cells. There are basically two kinds of chemical changes that can occur; tissue matter can be built, or it can be broken down.

These processes are called anabolism and catabolism. More specifically, anabolism is responsible for an organism’s growth, its maintenance, and the repair of its tissues. So when you cut yourself and your skin scabs over and heals, you’re seeing anabolism at work. Or if you grow taller or wider, that’s also evidence of anabolism.

In order to build tissue and repair it, however, anabolism requires energy, as well as material with which to build. This energy and building material comes from the breaking down of larger, more complex material, a process called catabolism. As well as producing energy and building material, catabolism also breaks down material for excretion from the body.

Both anabolism and catabolism are necessary for survival and good health.Understanding these processes can help one make good decisions about exercise and diet. For example, when an athlete trains, her muscle fibers break down. However, the daily recommended amount of protein is all that is needed to meet the anabolic and catabolic needs of the body and thus repair muscles fibers.

以上就是这篇托福阅读材料，同学们可以积累其中的词汇及优美句式，找到托福阅读段的主题句，了解托福阅读的几个出题点。托福阅读训练是个长期的过程。大家如果每天做几篇阅读，坚持下来，一定会有不小的进步。预祝大家能有一个好的阅读成绩。